/*******************************************************************************
 * Copyright 2017 Bstek
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License.  You may obtain a copy
 * of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations under
 * the License.
 ******************************************************************************/
package com.bstek.urule.model.function.impl;

import com.bstek.urule.RuleException;
import com.bstek.urule.Utils;
import com.bstek.urule.model.function.Argument;
import com.bstek.urule.model.function.FunctionDescriptor;
import com.bstek.urule.runtime.WorkingMemory;

import java.math.BigDecimal;
import java.util.Collection;


/**
 * @author Jacky.gao
 * @since 2015年7月22日
 */
public class MaxFunctionDescriptor implements FunctionDescriptor {
    private boolean disabled = false;

    public boolean isDisabled() {
        return disabled;
    }

    public void setDisabled(boolean disabled) {
        this.disabled = disabled;
    }

    @Override
    public String getLabel() {
        return "求最大值";
    }

    @Override
    public String getName() {
        return "Max";
    }

    @Override
    public Object doFunction(Object object, String property, WorkingMemory workingMemory) {
        Collection<?> list = null;
        if (object instanceof Collection) {
            list = (Collection<?>) object;
        } else {
            throw new RuleException("Function[max] parameter must be java.util.Collection type.");
        }
        BigDecimal max = null;
        Object maxObj = null;
        for (Object obj : list) {
            Object pvalue = Utils.getObjectProperty(obj, property);
            BigDecimal a = Utils.toBigDecimal(pvalue);
            if (max == null) {
                max = a;
                maxObj = obj;
            } else {
                int result = a.compareTo(max);
                if (result == 1) {
                    max = a;
                    maxObj = obj;
                }
            }
        }
        return maxObj;
    }

    @Override
    public Argument getArgument() {
        Argument p = new Argument();
        p.setName("集合对象");
        p.setNeedProperty(true);
        return p;
    }

}
